Vat dyestuffs of the anthracene series and process of making same.



UNITED STATES. PATENT OFFICE.

BACH-ON-THE-MAIN, GERMANY, ASSIGNORSTO THE CORPORATION OF CHEMISCHE iiFABRIK GRIESHEIM-ELEKTRON, OF FRANKFORT-ON-THE-MAIN. GERMANY.

VAT DYES'I'IIFFS OF THE ANTH-EAGENE SERIES AND PRO QESS OF MAKING SAME.

No Drawing.

To all whom 'it may concern Be it known that We, AUGUST LEOPOLD LASKA,ARTHUR Zrrsonnn, and ERNST J ULIUS RATH, chemists and doctors ofphilosophy, citizens of the German Empire, and residents ofOfl'enbach-on-the-Main, in the Grand Duchy of Hesse, Germany, withpost-office addresses VVilhelmsplatz 18, Friedrichstrasse 31,andKaiserstrasse 115, respectively, have invented new and usefulImprovements in Vat Dyestufis of the An,- thracene Series and Processesof Making Same, of which the followingis a specification. 1

Our invention relates to the manufacture and production of new vatdyestufls of the anthracene series, which are produced by acting withoxidizing agents upon azo dyestuffs, obtained by combining fi-diazocompounds of the anthraquinone series with {B-amino derivatives of theanthracene series;

In the first place the ortho-amino-azo dyestufi is oxidized to thepseudoazimino body; by using suitable oxidizing agents and by prolongedaction thereof the anthracene radical can be oxidized tothecorrespondent anthraquinone derivative. The simplest representativesof these bodies have the following formulae:

. Specification of Letters Patent. Application filed May 14, 1912.Serial No. 697,186.

Patented oet.' 29;1912.

t-ained are heated in 150 parts of uitro benzene at 100'C., and areoxidized by addition of a solution of 5jparts of sodium bichromate in200 parts of glacial acetic acid. when the blue color of the solution Iof the azo dyestuif is transformed into the brown-yellow colorof thepseudoazimid, the

reaction is stopped. Then the yellow-orange crystals which separate asthemass cools are filtered off, washed with glacial aceticacid and waterand dried. The dyestufl is soluble in concentrated sulfuric" acid .of66? B. to a brown solution, in fuming sulfuric acid to a brown-redsolution, in hot nitro- 1,000 parts of concentrated sulfuric acid .of

66 Be.,-are precipitated with 2,000 parts of ice and to this mass 100parts of pulverized.

potassium bichromate are gradually added at 90100' C. After boiling themixture for two hours, it is filtered, the solid matter washed, driedand recrystallized from nitro benzene, in which, when hotit is solubleto a pale-yellow solution. The body, which has the constitutionrepresented by Formula II, forms pale-yellow needles soluble inconcentrated sulfuric acid of 66 B. to an orange solution, in fumingsulfuric acid to a brown orange solution. The dyestufi yields with asolution of alkaline hydrosulfite a violet vat, dyeing cotton violetshades, which when oxidized become a yellow more feeble than the yellowobtained with the dyestuff of Example I.

Example III: The azo dyestufi precipitated in the form of blackish-greenflocks by combining the diazo compound corresponding with 45 parts ofQ-aminoanthraico uinone, with 21 parts of 2:6 diaminoanracene, is susended in water containing some caustic s a lye and to this mixture atemperature of until the black color solution of sodium hygochloriteisadded at'a is transformed into a yellowish-red. The oxidation productthus obtained (which contains probably two anthraquinone nuclei oneanthracene complex) is filtered,

and washed and used in, the form of paste for dyeing. The dyestufi formswhen, dry a in fuming'sulfuric acid to a brown solut1on..

From the violet-brown vat cotton is dyed black-brown shades which onsubsequent oxidation and treatment with a hot soap, solution becomesreddish-yellow of very good 'fastness.

Example IV: 50 parts of the dyestufl? obtained as in Example III aremixed With 250 parts of glacial acetic acid; to this mixture is added asolution of 50 parts of sodium bichromate in. 250parts of glacial aceticacid, and thewhole is boiled while gradually parts of concentratedsulfuric acid are dropped in, After boiling two hours the mixture ispoured into. water, the pre cipitated dyestuff (which contains probablythree.Qanthraquinone nuclei) is filtered, Washed and dried. It forms abrownish powder soluble in concentrated sulfuric acid of 66 B. to anorange solution and in'fuming sulfuric acid to a brown-ora1ige solution.From the violet-brown vat cotton is dyed deep brown shades which onsubsequent oxidation become yellow of Very good fastness. I a

Now what we claim and desire to secure by Letters Patent is' thefollowing:

1. The process of manufacturing vat dyestufi's of the anthraceneserlesconsisting 111 B. to a broWn-yellow nitrobenzene to a of very goodfast-ness.

In testimony, that we claim the foregoing acting with oxidizing agentsupon azo dye stuffs of the general formula:

2. As a new article of manufacture a vat dyestufl obtained by oxidationof the azo dyestufi' from li-diazoanthraquinone and B-aminoanthraceneindicated by the formula ,I l x -V W o which dyestuff dissolves inconcentrated sulfuric acid to a brown solution, in hot yellow solutionand yields with alkaline hydrosulfite solution a deepbrown vat fromwhich cotton is dyed brownblack shades, which by oxidation and treatmentwith a hot soap solution become'yellow as our invention, we have signedour names in presence of two witnesses, this 27th day of April, 1912.

AUGUST LEOPOLD LASKA. ARTHUR ZITSCHER. ERNST JULIUS BATH. Witnesses:

PETER LAUTENSOHLAGER, FRITZ Dison.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of ratents,

' Washington. D. G.

